Effect of sumac spice, Turkish coffee and yerba mate tea on the postprandial glycemic response to Lebanese mankoucheh

The aim of this study was to evaluate the individual effect of sumac (S), Turkish coffee (C) and yerba mate tea (Y) on the postprandial glycemic response to Lebanese mankoucheh, a common breakfast item in the Lebanese culture, and to determine the glycemic index (GI) of this food. S, C and Y are typical constituents of Lebanese meals. They may influence the postprandial glycemic response to carbohydrate-rich foods, but this has not been studied to date.

Twelve healthy normoglycemic adults consumed on separate days the following test meals: mankoucheh without S (M) with water (control meal); M prepared with single or double doses of S (S1 and S2) with water; M with 60 or 120 mL of unsweetened C; or M with 100 or 200 mL of unsweetened Y. Meals were prepared according to standardized recipes containing 50 g of available carbohydrates. Capillary blood glucose measures were taken at fast and six times after meal ingestion over a two hour period. The GI of mankoucheh was determined using a standard protocol.

The glycemic responses, evaluated at each time following meal ingestion, did not differ significantly among the seven meals, and neither did the incremental area under the glycemic response curves. The GI of mankoucheh was 61 ± 6, with no significant difference between M, M with S1 and M with S2.

This study contributes to better characterize the glycemic properties of S, C, Y and mankoucheh in conditions that closely resemble how these dietary items are used and consumed by some cultural groups.